Table 2 Quality assessment of included studies according to the SIGN cohort checklist
Item number | Description for cohort studies | Adams et al. [39] (2021) Longitudinal study | Rosencrans et al. [40] (2021) Cross-sectional study |
|---|---|---|---|
1.1 | The study addresses an appropriate and clearly focused question. (Yes, No, Can't say) | Yes | Yes |
1.2 | The two groups being studied are selected from source populations that are comparable in all respects other than the factor under investigation. (Yes, No, Can't say, Does not apply) | Yes | No |
1.3 | The study indicates how many of the people asked to take part, did so in each of the groups being studied. (Yes, No, Does not apply) | Can’t say | Does not apply |
1.4 | The likelihood that some eligible subjects might have the outcome at the time of enrolment is assessed and taken into account in the analysis. (Yes, No, Can't say, Does not apply) | Can’t say | Does not apply |
1.5 | What percentage of individuals or clusters recruited into each arm of the study dropped out before the study was completed | 13% | Does not apply |
1.6 | Comparison is made between full participants and those lost to follow up, by exposure status. (Yes, No, Can't say, Does not apply) | Does not apply | Does not apply |
1.7 | The outcomes are clearly defined. (Yes, No, Can't say) | Yes | Yes |
1.8 | The assessment of outcome is made blind to exposure status. If the study is retrospective this may not be applicable. (Yes, No, Can't say, Does not apply) | Does not apply | Does not apply |
1.9 | Where blinding was not possible, there is some recognition that knowledge of exposure status could have influenced the assessment of outcome. (Yes, No, Can't say) | Can’t say | Can’t say |
1.10 | The method of assessment of exposure is reliable. (Yes, No, Can't say) | Yes | Yes |
1.11 | Evidence from other sources is used to demonstrate that the method of outcome assessment is valid and reliable. (Yes, No, Can't say, Does not apply) | Yes | Yes |
1.12 | Exposure level or prognostic factor is assessed more than once. (Yes, No, Can't say, Does not apply) | Yes | Does not apply |
1.13 | The main potential confounders are identified and taken into account in the design and analysis. (Yes, No, Can't say) | No | No |
1.14 | Have confidence intervals been provided? (Yes, No) | Yes | No |
2.1 | How well was the study done to minimise the risk of bias or confounding? (High quality [+ +], Acceptable [ +], Low quality [0]) | 0 | 0 |
2.2 | Taking into account clinical considerations, your evaluation of the methodology used, and the statistical power of the study, do you think there is clear evidence of an association between exposure and outcome? (Yes, No, Can't say) | No | No |
2.3 | Are the results of this study directly applicable to the patient group targeted in this guideline? (Yes, No) | No | No |